A radio-frequency identification (RFID) tag generally contains two main components. The first is an antenna that receives and radiates an RF signal. The second component is an integrated circuit that may be mounted to a printed circuit board. The integrated circuit processes a received signal provided by the antenna, and provides a modulated output signal to be radiated by the antenna.
The RFID tag may be an active device (i.e., it includes a battery that powers the tag) or a passive device (i.e., does not include a battery and instead relies upon energy received by the antenna to induce a current that provides a voltage to operate the RFID tag). Notably, passive RFID tags are relatively inexpensive and are used ubiquitously.